Softimage has two default rigs, one for human characters and one for animal (or fantasy) characters. The rig for the human character has a head and neck, two arms and hands, a spine, a pelvis and two legs and feet. The rig is accompanied by numerous controllers and constraints, which assist in the animation of the character.
Character rigging in Softimage has been made very user friendly as one can easily modify the default rig as needed. The modifications to the rig can be done in one of two ways. Either one can create the basic biped rig and physically lengthen and adjust the bones as needed. Alternatively one can load a rig-building guide, this guide allows one to set up the “size and proportions to match your character, then create a rig for your character based on this guide” (Softimage Users guide). When using the biped guide one is able to, not only define the skeleton structure, but one can also set the volume control. The volume controls are “displayed as yellow splines with small manipulator cubes, which you can use to define the body’s volume” as seen below (Softimage users guide).
When using the default rig in Softimage the rig comes with constraints and controllers. This makes he rigging process much easier as one does not need to set up all the controllers but can rather add where necessary. Additionally one can add any desired bones to the rig that aren’t already there.
Once the rig fits the character as desired the rig must be attached to the character, this is done by enveloping the rig to the character. One will then need to paint weights on the character to ensure that the ‘skin’ of the character is attached in the desired way to the rig. However if one had attached volume controls to the rig it “can allow a character to reach extreme poses more easily than by weighting alone” (Softimage users guide).
It is evident that the default rig provides a wide range of options for modification. This allows the rig to be quite versatile and gives it the ability to be applied to numerous character designs.
Manually set up rigs
The rig I am going to discuss is not one I found on the internet but rather one which I made following the Softimage XSI tutorials.
The process of creating a rig manual starts with creating the bones to fit the character. It is important to make sure that one is in the correct view when creating the bones, as this will determine the direction in which the bones will bend. The structure of the bones was very similar to those in the default rig as I had a head and neck, two arms and hands, a spine, a pelvis, two legs and feet. The construction and number of bones used were very similar to those in the default rig. Therefore the skeleton of the manually made rig is basically the same as the default one.
Once the bones were in place one has to manually assign the controllers and constrains. This is important in ensuring that the rig can be animated effectively. One can add the controllers as desired but the main places would be feet, hands, pelvis neck and head. Once again the places where the tutorial suggested that the controllers were placed was in the same positions as those in the default rig. Finally, like when using the default rig, I needed to envelope the rig and paint on the weights.
Therefore the process of creating a manual rig was far more laborious than using the default rig, yet in both cases one arrives at the same destination. One could argue that through creating ones own rig it allows for more versatility that the default rig does. But, as previously discussed, the default rig allows one to modify it so vastly that there is no need to create a rig for that purpose. Additionally once the default rig is in place one still has the ability to add in bones, constraints and controllers where necessary.
Ultimately, the most important aspect of rigging is not manually creating a rig, but rather being conscientious when modifying the rig to fit the character. The better the rig fits the character the better the rig will be enveloped to the character. As discusses previously the volume control which one can apply to the default rig assists with this. If the volume of the character is suggested correctly, the more successful the enveloping will be.
Softimage. Softimage Users Guide. Autodesk, 2011. Software